Google has started rolling out the Health Guardian features it announced alongside the Pixel Watch 5 in August. Three of them are live in the Google Health app this week: blood pressure trends, insulin resistance trends and sleep breathing quality. Pixel Watch 3 and 4 owners get them too, and Google says they're free on all three. The blood pressure trend works from the pulse and movement the watch already records, with no cuff and no calibration, and it wants at least five days in a row of wear each week. The insulin resistance trend needs seven days of data in a month and runs on Google's largest sensor model, which Google trained on more than a trillion minutes of data from five million people who opted in.
None of this was switched on when the watch went on sale, so reviewers couldn't test it, and the wait isn't quite over. Both trends appear in the app on the first day of each month, and the first reports arrive in early October. Sleep breathing quality is quicker: each morning it shows how much of the night you spent breathing well. The blood pressure trend looks for a pattern over the month and can't take a reading on demand, which Samsung's Galaxy Watch can. Samsung's watch needs a blood pressure cuff to calibrate it every month. Fitbit Air owners get the blood pressure and insulin trends later this year, and only with a Google Health Premium subscription. Breathing Emergency Detection, which can call emergency services after a severe drop in blood oxygen, stays in Europe on the Pixel Watch 4 and 5. Google says it hasn't been cleared or evaluated by the FDA.